I'd want some more info before making a call. It could be a candle stick for all I can tell.
It looks like clay or porcelain I guess. What are the dimensions etc.?
It is not any known "Pin Type" insulator that is recognized in the Insulator Collecting hobby. It may be an insulator of sorts as Bill mentioned, a Capacitor Bushing or some such thing. There are lots of oddities out there.